This invention relates to an electric motor and in particular to a windshield wiper motor.
From German specification AS 2,658,746 an electric motor is known, in which a plug housing is fastened on a housing cap. Plug contacts are secured parallel to each other in the plug housing for connection to a mating plug. These plug contacts are formed as flat-pin terminals and arranged substantially parallel to the cap. Plug contacts for switch springs have a rectangularly projecting stud penetrating the cap. On this stud are riveted switch springs for a limit switch. The plug contacts for the motor supply leads are also positioned substantially parallel to the cap, whereby in the plug-in direction the motor supply leads are soldered to the end of the said flat-pin terminals.
However some motor vehicle manufacturers demand that the plug contacts be formed as round pins and/or receptacles, and in which the supply leads to these pins each projects into a bore of the pin transversely to the plug-in direction. A design according to the German specification AS 2,658,746 cannot easily be realized when such round pins are used. Therefore, until now soldering terminals have been provided on the motor housing on which is fixed a cable set which leads into a separate plug housing in which the round plug contacts are secured. However this design is very complicated in its production and assembly.
The invention is therefore based on the problem of developing an electric motor of the kind mentioned above in such a way that a cable set between the electric motor and a plug housing for the connection of the mating plug is omitted.
Economical production and assembly is only possible, if the switch springs can be directly fitted on the round pins and/or receptacles. However this is not possible, if these pins and/or receptacles are secured in parallel to the cap, because these pins and/or receptacles in most cases are formed as a part turned on a lathe and therefore cannot have a rectangularly projecting stud which could penetrate the cap. In accordance with the present invention these round pins and/or receptacles are fastened perpendicularly on the cap. An elongated portion of these round pins can then penetrate the cap so that the switch springs can be directly secured on the pins and/for receptacles. Thus a principal feature of the present invention is that the plug-in direction is changed in comparison with the prior art arrangements.
In one embodiment of the invention, all plug contacts are finally secured in the plug housing which itself is injection-moulded on the metal cap. In another embodiment of the invention only the pins and/or receptacles for the switch springs are fixed on the cap, while the pins and/or receptacles for the motor supply leads are carried on structural member which may be detachably secured on the outside of the cap. Thus pins and receptacles available on the market could be used, onto which are soldered the motor supply leads in a radially projecting way. The motor supply leads already provided with pins are then secured in this separate structural member and together with the latter fixed on the motor housing.
The separate structural member with the pins for the motor supply leads can be secured on the housing cap independently of the pins for the switch springs. However due to different tolerances it is not possible to use an integral counter plug for all pins. Therefore according to an especially preferred development of the invention this structural member has several bores. In some bores the pins for the motor supply leads are conducted and through other bores of this structural member the pins which are secured to the cap project. In this way it is ensured that the position of all pins and/or receptacles matches the arrangement of the corresponding pins and/or receptacles on the mating plug, so that an integral mating plug can be used without difficulty.